Households and businesses are supplied with 120-volt alternating current (AC) for use in providing electrical power to a number of devices, including small appliances and lighting. AC is typically supplied to a receptacle in a wall outlet. When the need for electrical power is located at a distance from the wall outlet, an extension cord may be used to deliver the power to where it is needed. One end of the cord plugs into the wall outlet receptacle, and the opposing end of the cord provides a receptacle for use in connecting the electrical load.
Not all electrical loads require AC. Some require direct current (DC). DC can be obtained from a wall outlet using a rectifier to rectify the AC. Many consumer electronic devices such as computers and cordless telephones use DC instead of AC.
The range of devices using AC or DC varies considerably and is growing. The number of devices that may be plugged into a wall outlet receptacle is limited. Various devices exist to increase the number of receptacles and in some cases a series of loads have their own receptacles.
For example, strings of holiday lights have a plug for the AC wall outlet at one end and a receptacle at the other end so that additional strings can be plugged into and thereby powered by the first string. This arrangement is not without its problems. The current that can be drawn by several strings put together can pose a hazard. Accodingly, many holiday light strings carry a fuse to limit current. However, when up to three strings are connected together the fuse used to limit current must still pass considerable current, perhaps six or seven amperes. Consequently, consumers who may use more than three strings to decorate have to use at least two receptacles and still run the risk of an electrical hazard.
Strings of holidays lights have been developed by the present inventor that operate on DC rather than AC. These strings have rectifiers in the plug or the first light socket that convert the incoming AC to DC and provide fuse protection for the circuit.
As the nature and variety of appliances and uses for electricity increases, so too does the desire to control use so that products are not damaged and good use is made of the electricity consumed. Also, there is greater interest in the measurement of electricity consumed. Thus, there is a need for a device that provides a convenient source of electrical current, including AC or DC, and potentially offers unprecedented control over the current being used.